The present invention relates to the structure of a casing for a printer, and particularly to the structure in which a case member constituting an external shape of the printer is fixed to a frame member for supporting component parts that function for printing.
A typical printer has a structure wherein the component parts such as a print head, a paper feeding roller, or the like, are supported by a frame member made of metal having high rigidity, This frame member is covered with a case member formed of elastic material such as plastic or the like.
The printer having such typical structure is assembled by fixing the case member to the frame member usually using several screws. Alternatively, it is assembled by engaging engagement members formed on the frame member with engagement members formed on the case member, and then fixing the case member to the frame member using several screws.
As described above, in a typical related art printer, tightening the several screws is necessary to fix the case member. However, attaching or detaching these screws, when the maintenance and check of the printer insides are performed, becomes troublesome. On the other hand, when the case structure has no screws, attachment and detachment of the case member is facilitated, but when the case member has been attached to the frame member, the unity of these members is not complete. As a result, noise is undesirably produced by contact between the frame member and the case member when the printer operates and, problematically, the case member is broken. Therefore, there is required a case structure of the printer wherein the attachment and detachment of the case member is facilitated and the unity of the case member in relation to the frame member is improved.
Accordingly, an object of the present invention is to provide a printer in which the unity of the case member in relation to the frame member, when the case member is attached to the frame member, is improved. Another object of the present invention is to facilitate the attachment and detachment of the case member with respect to the frame member.
In order to achieve the above and other objects, according to the present invention, there is provided a printer comprising;
a frame member for supporting components of the printer, the frame member including a first frame-side fitting member.
a first case member, which constitutes at least a part of an external shape of the printer and which covers a part of the frame member, the first case member including:
a first side wall forming a side face of the printer;
a second side wall having a first end thereof connected to the first side wall, and having a second end opposite to the first end, wherein the second end is a free end;
a third side wall, opposite to the second side wall, having a first end connected to the first side wall, and having a second end opposite to the third-side-wall first end, wherein the third-side-wall second end is a free end;
a first case-side fitting member provided on the second side wall so as to be located on one side of the first frame-side fitting member when the first case member covers the frame member; and
a second case-side fitting member provided on the third side wall so as to be located the other side of the first frame-side fitting member when the first case member covers the frame member; and
an elongated fitting plate, for fixing the first case member with the frame member by engaging with the first frame-side fitting member as well as with the-first and second case-side fitting members.
In this configuration, by inserting or pulling out the fitting plate, the attachment and detachment of the first case member in relation to the frame member can be readily performed.
Preferably, the printer further comprises a second case member, which constitutes another part of the external shape of the printer while covering another part of the frame member. The frame member includes:
a first side wall forming a side face of the printer, wherein said second-case-member first side wall opposes to the first side wall of the first case member;
a second side wall having a first end connected to the second-case-member first side wall, and having a second end opposite to the second-case-member-second-side-wall first end, wherein the second se-member-second-side-wall second end is a free end;
a third side wall, opposite to the second-case-member second side wall, having a first end connected to the second-case-member first side wall, and having a second end opposite to the second-case-member-third-side-wall first end, wherein the second-case-member-third-side-wall second end is a free end;
a third case-side fitting member provided on the second-case-member second side wall so as to be located on said one side of the first frame-side fitting member when the second case member covers the frame member; and
a fourth case-side fitting member provided on the second-case-member third side wall so as to be located on said other side of the first frame-side fitting member when the second case member covers the frame member.
The fitting plate fixes the first and second case members with the frame member by engaging with the first frame-side fitting member as well as with the first, second, third and fourth case-side fitting members.
Preferably, the frame member includes a second frame-side fitting member, with which the fitting plate engages when the first case member is fixed with the frame member.
In this configuration, since the fitting plate fits to the two engagement portions provided in the frame member, the degree of tightness between the frame member and the first and second case members can be improved.
Preferably, the first side wall of the first case member is urged so as to abut against the opposing face of the frame member, when the fitting plate engages with the respective fitting members.
In this configuration, since it is possible to fix the relative position of the first case member in relation to the frame member, looseness of the case member in relation to the frame member can be eliminated.
Preferably, the first frame-side fitting member is a through hole, through which the fitting plate is inserted.
In this configuration, the fitting plate can be reliably fitted to the first frame-side fitting member.
Preferably, the through hole is provided with a guide portion for guiding the fitting plate therein.
By the guide portion, the fitting plate can be readily caused to pass through the through hole.
Preferably, the frame member is attached to the first case member by moving the frame member from the second ends toward the first ends of the first-case-member second and third side walls The printer further comprises:
a first engagement member, for preventing the second ends of the is second and third side walls of the first case member from separating, when the first case member covers the frame member;
a second engagement member, for preventing the first case member from being detached from the frame member in a reversed direction of the attaching direction, wherein the second engagement member is located closer to the first ends of the first-case-member second and third side walls than is the first engagement member; and
a disengagement member, for releasing the engagement of the second engagement member, wherein the disengagement member is located closer to the first ends of the first-case-member second and third side walls than is the second engagement member.
In this configuration, when the first case member is attached to the frame member, the first and second engagement members are respectively in the fitting state, so that the open ends of the second and third side walls of the first case member are prevented from separating outwards. Additionally, simultaneously, the first case member is prevented from slipping out of the frame member in the direction opposite to the attaching direction of the first case member.
Preferably, the first engagement member includes a first engagement claw formed on the first case member, and a first engagement piece formed on the frame member, which is engaged with the first engagement claw. The second engagement member includes a second engagement claw formed on the first case member, and a second engagement piece formed on the frame member, which is engaged with the second engagement claw.
In this configuration, the engagement through use of the second engagement member an be made more reliable. Further, the engagement can be readily released.
Preferably, the printer further comprises a third engagement member, for preventing the first case member from being detached from the frame member in a direction orthogonal to the attaching direction, when the first case member covers the frame member.
Preferably, the third engagement member includes a guide member for guiding the first case member in the attaching direction with respect to the first case member
Preferably, the disengagement member is provided as cutoff portions, respectively formed on the second and third side walls of the first case member, through which fingers may be inserted to press the second and third side walls outwardly.
Preferably, the first case member includes a fourth side wall that extends substantially orthogonally to the first side wall so as to connect third ends of the second and third side walls. The first and second engagement members are provided in a portion closer to fourth ends of the second and third side walls, which is opposed to the third ends thereof.
Preferably, the printer further comprises a cover member, which constitutes another part of the printer while engaging with at least one of the first and second case members and the frame member, the cover member including a protrusion for restricting movement of the elongated fitting plate by engagement therewith.
In this configuration, the movement of the elongated fitting plate is restrained by attaching a fitting plate cover for covering this fitting plate, whereby attachment of the frame member to the case members becomes firmer.
Preferably, the cover member includes a first cover-side fitting member that is fitted with at least one of the second case member and the frame member through use of the engaging motion of the fitting plate. The protrusion is formed in the vicinity of the first cover-side fitting member.
This configuration suppresses the reduction in the degree to which the protrusion restrains the fitting plate, even if manufacturing error and aged deterioration occur in these members.
Preferably, the fitting plate includes a hole, with which the protrusion is engaged when the cover member is engaged with at least one of the second case member and the frame member.
Preferably, the fitting plate includes: a first portion extending in a first direction so as to include one end thereof; a second portion extending in the first direction so as to include the other end of thereof, and a third portion extending perpendicular to the first direction so as to connect the first and second portions. The first portion is engaged with the first frame-side fitting member as well as with the second, third and fourth case-side fitting members. The second portion is engaged with the second frame-side fitting member and the first case-side fitting member.
Preferably the cover member has a shape so as to extend along at least a part of the elongated fitting plate. The first cover-side fitting member is formed on one end portion of the cover member. The cover member includes a second cover-side member formed on the other end portion thereof, which is engaged with at least one of the first cover member and the frame member.
According to the configurations described above, the unity of the case member in relation to the frame member can be further improved by the foregoing fitting structure and also the attachment and detachment of the case member can be performed very readily.
Furthermore, tightening of the case member in relation to the frame member can be performed using a single elongated fitting plate without using a screw. Therefore, the attachment and detachment of the case member is performed very readily and the fixing metal fitting is prevented from slipping by the fitting plate cover for covering the fixing plate, so that though the above attachment and detachment is facilitated, the tightening can be completely performed.